It has been generally well known that a monomolecular layer can be formed by a liquid phase adsorption method. In this method, a substrate is dipped and held in a nonaqueous organic solvent containing a chemical adsorbent, and kept for a fixed number of hours for the reaction (EPC No. 0476543A2). In this method, a chemically adsorbed monomolecular layer is formed by a dehydrochlorination reaction between the hydroxyl groups on the substrate surface and the chlorosilyl groups of a chlorosilane-based adsorbent (surface active agent).
A dipping method has been employed for the above-noted conventional chemical adsorption method, and there has been a problem that a large amount of the adsorbent and a big tank are required for a large substrate.